This invention relates to locks, and particularly to apparatus for attaching a lock cylinder to a lock case. More particularly, this invention relates to an apparatus for mounting a lock body to a mortise lock case so that an interchangeable lock core in the lock body can be used to operate the mortise lock and for protecting the lock body and core from damage during an attack on the security of the lockset.
Lock cylinders are typically mounted in a lock case to prevent removal by unauthorized persons. It is known to use hidden setscrews to anchor a lock cylinder in a lock case as disclosed in U.S. Pat. No. 4,633,690 to Foshee. Advantageously, the security associated with such mortise locks is high because the hidden setscrews of the type disclosed in the Foshee '690 patent are only accessible to those persons authorized and able to remove the interchangeable FIG. 8 lock core from its home in the lock body to gain access to the hidden setscrews.
One problem with conventional mortise locks has been anchoring a lock cylinder that is different than the original equipment lock cylinder in the cylinder lock mounting hole provided in the mortise lock case. Many times, the owner of a mortise lock will decide to replace the lock cylinder that came with the mortise lock with a higher quality and higher security lock cylinder. For example, to increase the security of a mortise lockset, it would be desirable to replace a lock cylinder that is anchored to a lock case by means of an exposed setscrew with a higher security lock cylinder that is configured to be anchored to the same lock case by means of a hidden setscrew. The problem has been that, throughout the world and particularly outside the United States, conventional lock cylinders having hidden anchoring setscrews are not adapted to be mounted in many conventional mortise lock cases. Accordingly, a cylinder lock that could be retrofitted easily into a wide variety of lock cases and anchored in place in the lock case using hidden anchoring means would be a welcomed improvement.
According to the present invention, a lock cylinder apparatus is provided and configured to be mounted in a lock case having first and second exterior side walls arranged in spaced-apart parallel relation. The lock cylinder apparatus includes a first lock cylinder assembly mounted on the first exterior side wall of the lock case, a second lock cylinder assembly mounted on the second exterior side wall of the lock case, and means for coupling the first lock cylinder assembly to the second lock cylinder assembly to trap the lock case therebetween so that the first and second lock cylinders are rigidly fixed to the lock case and positioned to engage and operate an internal locking mechanism contained in the lock case.
The first lock cylinder assembly includes a first lock body formed to include a cavity for the reception of an interchangeable lock core and a first adaptor ring around the first lock body. The first adaptor ring includes an inner annular end wall engaging the first exterior side wall. The first adaptor ring is formed to include a central aperture receiving the first lock body therein and means for threadedly engaging the first lock body to fix the first lock body in the central aperture of the first adaptor ring. The coupling means includes a threaded member extending through the lock case and having a first end connected to the first adaptor ring and a second end connected to the second lock cylinder assembly.
In preferred embodiments, the first lock body includes an exterior side wall and is formed to include a bore extending between the cavity in the first lock body and the exterior side wall to define a hidden setscrew-receiving opening in the exterior side wall. The first adaptor ring includes an outer annular end wall facing away from the first exterior side wall of the lock case and surrounding the first lock body. The outer annular end wall is formed to include a radially outwardly extending channel. The first lock cylinder assembly further includes a hidden setscrew that is located in the bore and is movable therein to engage the radially outwardly extending channel formed in the first adaptor ring and anchor the first lock body in a non-rotatable mounted position to the first adaptor ring.
The first lock body includes an outer end away from the first adaptor ring and an annular lip on the outer end. The first lock cylinder assembly further includes a tubular cylinder ring surrounding the first lock body and having an inner end abutting the outer annular end wall of the first adaptor ring and an outer end lying in close proximity to the annular lip formed on the outer end of the first lock body. This tubular cylinder ring protects the lock from attack. Spring means is provided for yieldably urging the tubular cylinder ring toward the first adaptor ring to load the inner end of the tubular cylinder ring against the outer annular end wall of the first adaptor ring so that the tubular cylinder ring is restrained from movement relative to the first adaptor ring and the first lock body to minimize rattling. Illustratively, the spring means engages the annular lip and the outer end of the tubular cylinder ring.
The second lock cylinder assembly includes a second lock body formed to include a cavity for the reception of another interchangeable lock core and a second adaptor ring around the second lock body and the second end of the threaded member engages the second adaptor ring. Illustratively, the threaded member is arranged to interconnect the first and second adaptor rings.
The coupling means further includes a mounting pin appended to the inner annular end wall of the first adaptor ring and arranged to engage the second adaptor ring to set a minimum standoff spacing between the first and second adaptor rings to prevent deformation of the lock case during coupling of the first and second lock cylinders to one another using the coupling means. Illustratively, two mounting pins are used and arranged to lie on either side of the threaded members. In a preferred embodiment, the mounting pin is arranged to extend into a blind hole formed in the second adaptor ring. The first exterior side wall of the lock case is formed to include a notch and a border edge around the notch and the coupling means is situated to place the mounting pin in the notch and in engagement with the border edge around the notch to block rotation of the first lock cylinder about a longitudinal axis of the first lock cylinder and relative to the first exterior side wall of the lock case.
Additional objects, features, and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of a preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived.